Apparatus for developing high fluid pressure

ABSTRACT

A PRESSURE DEVELOPING APPARATUS COMPRISES A CASING HAVING FIRST AND SECOND INTERCOMMUNICATING CHAMBERS EXTENDING AT RIGHT ANGLES TO ONE ANOTHER AND FILLED WITH A LIQUID. ONE CHAMBER CONTAINS A SLIDABLE PISTON THEREIN ADAPTED FOR BEING EXTERNALLY ACTED ON TO PRESSURIZE THE LIQUID IN THE CHAMBERS, AND THE OTHER CHAMBER CONTAINS   THE MATERIAL TO BE PRESSURIZED. THE PISTON HAS A LIQUID INLET AND A BORE LEADING TO THE FIRST CHAMBER, AND THE INLET IS CLOSABLE BY A VALVE WHICH IS SUBJECTED TO THE PRESSURE OF THE LIQUID.

May 23, 1972 J. MARTRIER APPARATUS FOR DEVELOPING HIGH FLUID PRESSURE 2 Sheets-Sheet 1 Filed May 18, 1970 FIG/ y 23, 1972 LMARTRIER APPARATUS FOR DEVELOPING HIGH FLUID PRESSURE 2 Sheets-Sheet 2 Filed May 18 1970 United States Patent 3,664,801 APPARATUS FOR DEVELOPING HIGH FLUID PRESSURE Jean Martrier, Bourges, France, assignor to Etat Francais Filed May 18, 1970, Ser. No. 38,348 Claims priority, application France, May 23, 1969, 6916845 Int. Cl. B30b 5/02, 11/32 U.S. Cl. 425-405 9 Claims ABSTRACT OF THE DISCLOSURE BRIEF SUMMARY OF THE INVENTION The invention relates to apparatus for isostatic compression of material, such as powder products.

Currently available isostatic compression apparatus can be divided into two groups:

(I) Compressor apparatus In this case the required high pressure is supplied to the chamber containing the product to be compressed by means of a high-pressure compressor.

The disadvantages of such apparatus are numerous and include the employment of a high-pressure generator separate from the chamber which involves the following drawbacks:

the compression demands constant maintenance;

high pressure exists externally of the main chamber which increases the risks of leakage through joints and piping, especially if the isostatic fluid has to be heated which produces a drop in the coefiicient of viscosity at high temperatures;

excessive floor space is required by the apparatus.

The only advantage of such an arrangement is its capability of the placement of a mass of the product to be compressed almost equal in volume to the interior of the high-pressure chamber, therefore providing practically a 1:1 efiiciency ratio of useful volume to inside chamber volume.

(2) Pressure booster apparatus This apparatus operates on Pascals principle, and neglecting friction, it permits the attainment of high pressures.

This apparatus has the drawback that because of the not inconsiderable compressibility of liquids under high pressure, the apparatus has to be provided with considerable space .for the stroke of the piston. Consequently, the pressure chamber required is considerable and the ratio of effective volume to interior volume of the chamber is less than in the foregoing case.

An object of the present invention is to provide an isostatic compression apparatus devoid of the drawbacks of the known systems and offering the following advantages:

(a) constant serviceable volume Whatever the amount of pressure applied to the material under treatment. This 3,664,801 Patented May 23, 1972 is achieved by means of two intercommunicating chambers at right angles to one another. One chamber is vertical and contains the piston and serves as a liquid reserve, while the other chamber is horizontal and contains the material to be compressed;

(b) the form of the chambers reduces the space occupied by the apparatus and facilitates removal of the compressed material;

(c) the high pressure is confined essentially to the inside of the chambers;

(d) the seals and remote control apparatus for the compression operations are sturdy and eflicient;

,(e) the power required for moving the piston can be supplied by a conventional single-action press, jack, low-pressure hydraulic pump, etc.;

(f) the apparatus is portable and can be used on any commercial press with a suitable stroke.

In accordance with the invention, the pressurizing apparatus comprises a casing defining first and second intercommunicating chambers extending at right angles to one another, a piston slidably supported in one chamber for pressurizing a fluid contained in the chambers, and means replaceably in said casing for furnishing access to the other of said chambers for insertion therein and removal therefrom of materials to be pressurized.

The piston has a bore and an inlet for admission of fluid into the chambers, and valve means is provided for closing the inlet.

A heater means is provided on the casing for supplying heat to the material, if desired, during isostatic compression thereof.

Sealing means is provided for the chambers and the sealing means is responsive to the pressure of the fluid in the chambers to intensify the sealing of the chambers.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a side elevation view, partly in section, of the compression apparatus according to the invention,

FIG. 2 shows, in section, a portion of the casing of the apparatus of FIG. 1,

FIG. 3 shows, in section, the piston of the apparatus of FIG. 1, and

FIG. 4 is a diagrammatic sectional view of a portion of the apparatus of FIG. 1.

DETAIIJED DESCRIPTION Referring to the drawing, there is shown a casing 1 of T shape and formed, 'for example as a one piece casting. The casing contains two intercommunicating hollow, cylindrical, chambers 2 and 3 extending at right angles to one another.

The chamber 2 is vertical and slidably receives a piston 4, while the material to be compressed 5 is contained in chamber 3 which is horizontal.

A sealing member 6 is threadably engaged in the casing toseal the chamber 3 and a nut or other mechanical device can be engaged in the casing to secure and compress the sealing member in the casing whereby to seal the chamber 3. The member 6 is removable from the casing to insert material 5 into chamber 3 and to remove compressed material therefrom.

An annular heater 7 surrounds the chamber 3 to transmit heat to the material 5 in chamber 3 to effect compression under heat of material 5 when this is desirable.

T he piston 4 is adapted for external connection with a press or jack or the like to transmit pressure to the fluid 8 (generally a liquid, such as oil) in the chambers 2 and 3. The piston 4 also serves the function of inlet of fluid to the chambers. In this respect the piston contains an insert 9 forming a bore or passageway 10 leading to a fluid inlet 11. A valve 12 in the form of a ball serves to close the inlet 11 under the action of a spring 13 when the chambers are not under pressure, and by the hydraulic pressure developed in the fluid 8 and applied to the valve 12 when the piston 4 is active.

A seal ring 14 is placed in the walls of chamber 2 around piston 4, and the presence of the bore pressurizes the interior of piston 4 and causes the piston to hear more intensely on seal ring 14 thereby preventing leakage past seal 14 during pressurization, which insures leak-tightness at seal 14.

The piston 4 includes depending stems 15 which are slidably engaged in the casing 1 for guiding the displacement of the piston and insuring pure axial movement thereof.

The sealing member 6 which leak-tightly seals the end of chamber 3 has a portion 16 extending into chamber 3 and portion 16 has a blind bore 17 therein as shown in FIG. 2. The sealing member 16 is constituted of a resilient material, such as rubber, and a seal 18 is mounted on portion 16 in the Wall of chamber 3. During pressurization, the blind bore 17 is subjected to the pressure of the fluid and the portion 16 is deformed outwardly to be compressed against seal 18 whereby to insure the leaktightness of chamber 3.

The casing is mounted on a roller bearing 19 to facilitate transport of the apparatus from one place to another to enhance its portability.

In order to depressurize the chambers and remove the fluid, a discharge device 20 is provided. The device 20 is mounted in a passage 21 which leads to chamber 3 and is subject to the pressure of the fluid therein and the device 20 comprises a ball valve 22 acted on by a spring 23 to close a passage 24 leading externally of the casing. A manual control member 25 is threadably engaged in casing 1 and has a stem 26 facing ball 22 such that as the control member is threadably advanced in casing 1, the stem will push ball 22 away from its seat whereupon passage 24 will be open for discharge of the fluid from the chambers.

The apparatus is operative for many purposes and with various types of displacement devices, such as single acting presses having suflicient stroke. The apparatus can be used for (a) isostatic compression of powdery materials such as hot or cold compression of explosive powders,

(b) formation of products under high hydraulic pressure,

and

(c) producing high hydraulic pressure by the thrust on the piston 4.

What is claimed iszl 1. Pressurizing apparatus comprising a casing defining flrst and second intercommunicating chambers extending at right angles to one another, a piston slidably supported in one chamber for pressurizing a fluid contained in the chamber, means replaceably in said casing for furnishing access to the other of said chambers for insertion therein and removal therefrom of materials to be pressurized, a sealing means in said casing engaging said piston to seal said one chamber, said piston being provided with a bore exposed to the fluid pressure in the chamber such that said piston compresses said sealing means under the pressure of the fluid in said bore to intensify the sealing of said one chamber.

2. Pressurizing apparatus as claimed in claim 1 Wherein said piston has an inlet leading to said bore for admission of fluid into said chambers, and valve means in said inlet for closing the same.

3. Pressurizing apparatus as claimed in claim 2 comprising an insert threaded into said piston at said bore and defining clearance therewith, said insert having a passageway leading from said one chamber to said clearance.

4. Pressurizing apparatus as claimed in claim 3 wherein said valve means comprises a valve member, and a spring engaged by said insert and acting on said valve member to close said inlet.

5. Pressurizing apparatus as claimed in claim 4 Wherein said valve member is a ball.

6. Pressurizing apparatus as claimed in claim 1 comprising heater means on said casing for supplying heat to the material during compression thereof.

7. Pressurizing apparatus as claimed in claim 1 comprising valve means in communication with one of said chambers for selectively communicating the same with ambient atmosphere to depressurize the chambers, said valve means including a spring-loaded valve member exposed to the pressure of the fluid in the chambers and urged to closed position thereby, and a manually operated control member for engaging the valve member to open the same against the pressure of the spring action thereof.

8. Pressurizing apparatus as claimed in claim 1 comprising bearing means for support of said casing to render the same portable.

9. Pressurizing apparatus as claimed in claim 1 comprising sealing means for said other chamber including a seal in said casing, said means for furnishing access to the other of the chambers comprising a removable member in said other chamber engaging said seal and having a bore exposed to the pressure of said fluid for deforming said removable member under said pressure to press said member against said seal and intensity the sealing of said other chamber.

References Cited UNITED STATES PATENTS 2,851,725 9/1958 Bauer 18-16.5 X 2,648,125 8/1953 McKenna et a1. 1 8-5 H UX 3,230,286 1/ 1966 Bobrowsky 18-Dig. 26 3,319,292 5/1967 Witkin 18-5 H 3,462,797 8/1969 Asbury 18-5 H UX 3,494,160 2/1970 Tominoga et a1. 72-60 3,132,379 5/1964 Crane 18-165 3,249,966 5/1966 Ludwig 18-16 R 3,123,862 3/ 19 64 Levey 18---Dig. 2 6 3,200,442 8/ 1965 Haller 18-16.5 2,338,491 1/1-944 Cutler 18-16.5 2,883,703 4/ 1959 Frank 18-167 3,189,954 6/1965 Piet 18-5 HX 2,942,298 6/1960 Loedding LS-Dig. 26

J. HOWARD FLINT, JR., Primary Examiner US. Cl. X.R.

425-1, 78 Dig. 26; 72-60; 29-421 E 

